1. Field of the Invention
The invention relates generally to electrical enclosures and, more particularly, to electrical enclosures that are coupled to electrical busways. The invention also relates to support assemblies for electrical enclosures.
2. Background Information
Electrical switching apparatus used in power distribution systems are often mounted within an electrical enclosure (e.g., without limitation, a panelboard; a load center; a meter center) either individually or in combination with other switchgear (e.g., without limitation, circuit switching devices and circuit interrupters such as circuit breakers, contactors, motor starters, motor controllers and other load controllers).
The electrical enclosure is typically coupled to, and supported by, a structure such as, for example, a wall or an electrical busway. Electrical power is supplied to electrical equipment housed by the electrical enclosure from a plurality of electrical conductors. When an electrical busway is employed, the electrical conductors are typically disposed within an elongated rail structure. The electrical enclosure is mechanically coupled to the elongated rail structure. The electrical equipment housed within the electrical enclosure is electrically connected to the electrical conductors of the electrical busway using suitable electrical connectors.
Some known electrical enclosures are supported exclusively by the electrical busway. Among other disadvantages, such designs are limited by the size and/or weight of the electrical enclosure. For example, a relatively large or relatively heavy electrical enclosure could place an excessive bending moment and associated stress on the electrical busway and associated hardware (e.g., without limitation, clamps; brackets; fasteners), as well as on the electrical connections between the electrical busway and electrical equipment housed within the electrical enclosure.
In an attempt to overcome this structural limitation, one prior proposal attached hangers from an overhead structure (e.g., without limitation, the ceiling; rafters of a building). However, this proposal is limited by overhead obstructions and/or by the amount of weight the overhead structure is capable of supporting.
Another prior proposal rigidly mounted the electrical enclosure to a nearby structure (e.g., without limitation, a wall), using suitable mechanical hardware (e.g., without limitation, clamps; brackets; fasteners). However, mounting the electrical enclosure in a rigid, fixed position on the wall does not allow it to move with the electrical busway. Accordingly, if such busway moves, the hardware coupling the electrical enclosure to the busway and/or the electrical connections between the busway and electrical components housed within the electrical enclosure, can be undesirably subjected to excessive forces and stress.
Another problem relating to proper support of the electrical enclosure is that minimal space is available between the back of such enclosure and the wall or other suitable structure to which the enclosure is to be mounted. It is, therefore, difficult to secure the enclosure to the wall or structure, particularly after it has already been coupled to the electrical busway.
There is room, therefore, for improvement in electrical enclosures such as, for example, load centers. There is also room for improvement in support assemblies for electrical enclosures.